1. Field of the Invention
The present invention relates to a construction of an ink jet recorder, and more particularly to a construction of an ink jet recorder which mounts a recording head as well as an ink container on a carriage moving along a record medium.
2. Description of the Prior Art
The ink jet recorder as well as a wire dot recorder and a thermal recorder have been used as output devices of electronic equipments such as printers or facsimile machines. The ink jet recorder is noiseless and suitable for high speed printing and easily prints a color image. Accordingly, it has been used as a high performance recorder.
In the ink jet recorder, ink in an ink container is supplied to a recording heads and a drive element for discharging the ink on the recording head is driven in accordance with a record signal such as a print pattern so that ink droplets are discharged toward a record medium (paper).
In order to reduce weight of the recorder and simplify the construction, the ink container is mounted on a carriage.
When the ink is continuously supplied to the recording head during the record operation, a vacuum is created in the ink container and supply of the ink to the recording head is not sufficient or is unstable and print quality may be degraded. Accordingly, it is required to provide vacuum prevention means for maintaining a constant pressure (e.g. atmospheric pressure) in a space on the ink level in the ink container.
If a vent port is provided in the ink container as the vacuum prevention means, the ink solvent vaporizes during a long stand-by period and an ink viscosity increases, or foreign materials such as dusts are introduced into the ink container. As a result, the print quality is degraded when the print operation is resumed.